[syzbot] [jfs?] kernel BUG in jfs_unlink

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    2c9b3512402e Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13ffb6b5980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f4925140c45a2a50
dashboard link: https://syzkaller.appspot.com/bug?extid=41b43444de86db4c5ed1
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/3c29a41eae6b/disk-2c9b3512.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/938da4f6bc30/vmlinux-2c9b3512.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4f9521f6c1ef/bzImage-2c9b3512.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+41b43444de86db4c5ed1@xxxxxxxxxxxxxxxxxxxxxxxxx

BUG at fs/jfs/namei.c:513 assert(ip->i_nlink)
------------[ cut here ]------------
kernel BUG at fs/jfs/namei.c:513!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 PID: 9192 Comm: syz-executor Not tainted 6.10.0-syzkaller-11185-g2c9b3512402e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:jfs_unlink+0xafd/0xb30 fs/jfs/namei.c:513
Code: e8 18 6f 6a 08 e8 53 c2 76 fe 48 c7 c7 e0 96 02 8c 48 c7 c6 a0 94 02 8c ba 01 02 00 00 48 c7 c1 20 97 02 8c e8 d4 6f 67 08 90 <0f> 0b e8 2c c2 76 fe 48 c7 c7 e0 96 02 8c 48 c7 c6 a0 94 02 8c ba
RSP: 0018:ffffc90003367be0 EFLAGS: 00010246
RAX: 000000000000002d RBX: 0000000000000000 RCX: f6009ee609a28400
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc90003367d10 R08: ffffffff8173a15c R09: 1ffff9200066cf1c
R10: dffffc0000000000 R11: fffff5200066cf1d R12: 0000000000000000
R13: ffffc90003367c60 R14: 1ffff9200066cf8c R15: ffff88807a381fd8
FS:  000055558b529500(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f20933a178 CR3: 0000000065f88000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 vfs_unlink+0x365/0x650 fs/namei.c:4422
 do_unlinkat+0x4ae/0x830 fs/namei.c:4486
 __do_sys_unlink fs/namei.c:4534 [inline]
 __se_sys_unlink fs/namei.c:4532 [inline]
 __x64_sys_unlink+0x47/0x50 fs/namei.c:4532
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbcb13751a7
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffeb18f8828 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbcb13751a7
RDX: 00007ffeb18f8850 RSI: 00007ffeb18f88e0 RDI: 00007ffeb18f88e0
RBP: 00007ffeb18f88e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffeb18f99d0
R13: 00007fbcb13e344c R14: 000000000005216e R15: 0000000000051cc6
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:jfs_unlink+0xafd/0xb30 fs/jfs/namei.c:513
Code: e8 18 6f 6a 08 e8 53 c2 76 fe 48 c7 c7 e0 96 02 8c 48 c7 c6 a0 94 02 8c ba 01 02 00 00 48 c7 c1 20 97 02 8c e8 d4 6f 67 08 90 <0f> 0b e8 2c c2 76 fe 48 c7 c7 e0 96 02 8c 48 c7 c6 a0 94 02 8c ba
RSP: 0018:ffffc90003367be0 EFLAGS: 00010246
RAX: 000000000000002d RBX: 0000000000000000 RCX: f6009ee609a28400
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc90003367d10 R08: ffffffff8173a15c R09: 1ffff9200066cf1c
R10: dffffc0000000000 R11: fffff5200066cf1d R12: 0000000000000000
R13: ffffc90003367c60 R14: 1ffff9200066cf8c R15: ffff88807a381fd8
FS:  000055558b529500(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcdd237ef0 CR3: 0000000065f88000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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